Anti-Inflammatory Compounds from Vietnamese Piper bavinum

This study reports the anti-inflammatory activity-guided fractionation of the aerial part of Piper bavinum C. CD. (Piperaceae) that led to the isolation of eight secondary metabolites (1-8). The chemical structures of 1-8 were established mainly by NMR and mass spectra. Compound 5 was isolated from P. bavinum for the first time. All the isolated compounds were evaluated against LPS-induced NO production in macrophage RAW 264.7 cells in vitro. Among them, compound 4 showed the most potent inhibitory activity against the LPS-induced NO production with an IC50 value of 5.2 mu M followed by compound 5 that inhibited NO production with an IC50 value of 13.5 mu M. In the protein levels, compound 4 suppressed LPS-induced COX-2 and iNOS expressions in a dose-dependent manner. The results suggested that P. bavinum and its constituents might exert anti-inflammatory effects.